The present invention relates to a steel laminate gasket with associated beads for an internal combustion engine.
Efficiency of an engine has increased progressively, and in association therewith, pressure in combustion chamber has increased. As a result, a large amount of pressure is applied to a gasket situated between engine blocks. In order to securely seal between the engine blocks, it is required that the gasket provides strong sealing pressure when the gasket is tightened.
One method for providing high sealing pressure is that a plurality of steel plates with beads therein is laminated vertically. In this case, high sealing pressure is formed only around an area where the beads are located. Since the width of the bead is narrow, a narrow high pressure area is formed.
In Japanese Utility Model Publication No. 62-82462 published on May 26, 1987, a gasket comprises at least three steel plates, wherein upper and lower plates include beads with different sizes, and a middle plate is situated between the upper and lower plates. Since the sizes of the beads are different, the beads provide different sealing pressure at areas around the beads. The beads with different sizes do not cooperate together.
In Japanese Utility Model Publication No. 55-124659 published on Sep. 4, 1980, a gasket comprises at least four plates, wherein two middle plates are provided with beads with the same size. The middle plates are stacked together so that the two beads provide strong pressure when tightened.
Another method for securely sealing around a high pressure area is that an area around the high pressure is widely sealed. In this respect, if the width of a bead is made wide, when the gasket is tightened, the bead may collapse by pressure applied thereto, so that the bead can not provide sufficient and even sealing pressure around the high pressure area.
Therefore, one object of the present invention is to provide a steel laminate gasket which can provide strong, wide and even sealing pressure.
Another object of the invention is to provide a steel laminate gasket as stated above, which can be manufactured simply and economically.
Further objects and advantages of the invention will be apparent from the following description of the invention.